1. Field of the Invention
This invention relates to an electric pulse signal (to be hereinafter called a pulse signal) computing and processing apparatus, and more particularly to a pulse signal amplitude storage-holding apparatus which is simple in construction and capable of storing and holding for a sufficiently long time the pulse magnitude of a pulse signal in comparison with a pulse width thereof.
2. Description of the Prior Art
A conventional digital processing apparatus which has been used as an apparatus for storing and holding for a long time the pulse magnitude of a pulse signal is shown in a schematic block diagram in FIG. 1, in which the pulse magnitude (the voltage v.sub.in) of an input electric pulse signal (to be hereinafter called the pulse signal) V.sub.in is compared with the preset reference voltage values v1 to vn by a comparison means 2 comprising comparators C1 to Cn, the binary logic output signal from the comparison means 2 is stored in a storage means 3 comprising storage units M1 to Mn comprising flip-flop circuits or the like, and thereafter, a discriminator 4 decides whether or not an output of each of the n-number of storage units M1 to Mn exists, thereby outputting from an output terminal 5 a pulse signal V.sub.out of pulse magnitude v.sub.out (=v.sub.in). Such an apparatus decides the resolution of the input pulse signal V.sub.in by the division number used for dividing the pulse magnitude of input pulse signal V.sub.in into quantized portions. Accordingly, a large division number is required in order to store with sufficiently high accuracy the amplitude level of the pulse signal to be stored, whereby the apparatus becomes large scale.
On the other hand, FIG. 2 is a basic circuit diagram when an analog method is used to store the pulse magnitude of pulse signal by using the pulse signal to charge a capacitor, in which a pulse signal amplitude storage-holding means 6 (to be hereinafter called the storage-holding means) comprises a charging resistance 7 of a resistance value Rc and a storage capacitor 8 of a capacitance value C. The pulse signal V.sub.in which is fed into a terminal 9 is used to quickly charge the storage capacitor 8 through the charging resistance 7 so that voltage across the storage capacitor 8 reaches the pulse magnitude v.sub.in of pulse signal so as to become constant. Thereafter, the electric charge stored in the storage capacitor 8 is discharged through a load resistance 10 of a resistance value R.sub.L which is connected external to of storage-holding means 6. In addition, in FIG. 2, the waveform of the output signal V.sub.out is expanded so as to be sufficiently larger in its pulse width than the input pulse signal V.sub.in (v.sub.out =v.sub.in). The storage-holding means 6 is required to have the characteristic that the pulse magnitude v.sub.in of the input pulse signal V.sub.in is stored in a sufficiently short time in comparison with the pulse width tp thereof, and that the pulse magnitude v.sub.in of the pulse signal V.sub.in is held for a sufficiently longer time in comparison with the pulse width tp thereof, which is given by the following equation: EQU Rc.multidot.C&lt;&lt;tp&lt;&lt;RL.multidot.C (1)
Usually, Rc and RL are selected such that Rc&lt;&lt;RL, but in the FIG. 2 construction, the equation (1) becomes unsatisfied as the pulse width tp of the input pulse signal V.sub.in becomes shorter and the pulse magnitude holding time becomes longer. Hence, a single analog storage-holding means cannot constitute a pulse signal amplitude storage-holding apparatus (to be hereinafter called the pulse amplitude holding apparatus).